if _, err := r.f.Seek(r.offset+offset, 0); err != nil {
		return err
	}
	return binary.Read(r.f, r.order, data)
}

func (r loadCmdReader) WriteAt(offset int64, data interface{}) error {
	if _, err := r.f.Seek(r.offset+offset, 0); err != nil {
		return err
	}
	return binary.Write(r.f, r.order, data)
}

// machoCombineDwarf merges dwarf info generated by dsymutil into a macho executable.
//

}

// WriterTo is the interface that wraps the WriteTo method.
//
// WriteTo writes data to w until there's no more data to write or
// when an error occurs. The return value n is the number of bytes
// written. Any error encountered during the write is also returned.
//
// The Copy function uses WriterTo if available.
type WriterTo interface {
	WriteTo(w Writer) (n int64, err error)
}

// hide the WriteTo method of that other type.
type noWriteTo struct{}

// WriteTo hides another WriteTo method.
// It should never be called.
func (noWriteTo) WriteTo(io.Writer) (int64, error) {
	panic("can't happen")
}

// fileWithoutWriteTo implements all the methods of *File other
// than WriteTo. This is used to permit WriteTo to call io.Copy
// without leading to a recursive call to WriteTo.

	for _, tc := range [...]struct {
		Name string
		r    Reader
	}{
		{"not a WriterTo", Reader(nil)},
		{"a WriterTo", struct {
			Reader
			WriterTo
		}{}},
	} {
		nc := NopCloser(tc.r)

		_, expected := tc.r.(WriterTo)
		_, got := nc.(WriterTo)
		if expected != got {
			t.Errorf("NopCloser incorrectly forwards WriterTo for %s, got %t want %t", tc.Name, got, expected)
		}
	}
}

			out.Write32(s.prot2)
			out.Write32(s.nsect)
			out.Write32(s.flag)
		} else {
			out.Write32(LC_SEGMENT)
			out.Write32(56 + 68*s.nsect)
			out.WriteStringN(s.name, 16)
			out.Write32(uint32(s.vaddr))
			out.Write32(uint32(s.vsize))
			out.Write32(uint32(s.fileoffset))
			out.Write32(uint32(s.filesize))
			out.Write32(s.prot1)
			out.Write32(s.prot2)
			out.Write32(s.nsect)
			out.Write32(s.flag)
		}

		return nil, err
	}

	// Establish file header and initial data area if not already present.
	if info.Size() < minFileLen {
		if _, err := f.WriteAt(hdr, 0); err != nil {
			return nil, err
		}
		// Write zeros at the end of the file to extend it to minFileLen.
		if _, err := f.WriteAt(m.zero[:], int64(minFileLen-len(m.zero))); err != nil {
			return nil, err
		}
		info, err = f.Stat()
		if err != nil {
			return nil, err

	for i := range w.buffer {
		delete(w.buffer, i)
	}
	w.wg.Wait()
	return err
}

type writerAt struct {
	w      *io.PipeWriter
	r      *io.PipeReader
	wg     *sync.WaitGroup
	buffer map[int64][]byte
	err    error

	nextOffset int64
	m          sync.Mutex
}

func (w *writerAt) WriteAt(b []byte, offset int64) (n int, err error) {
	w.m.Lock()
	defer w.m.Unlock()

	fmt.Fprintf(r.getState().err, format, args...)
}

// Write emits a slice to the reporter's output stream.
//
// Any error is returned to the caller, and does not otherwise affect the
// reporter's exit code.
func (r *reporter) Write(p []byte) (int, error) {
	return r.getState().out.Write(p)
}

// Report emits a non-nil error to the reporter's error stream,

			err = closeErr
		}
	}()
	if err := hf.Truncate(int64(len(hash))); err != nil {
		return err
	}
	if _, err := hf.WriteAt([]byte(hash), 0); err != nil {
		return err
	}
	return nil
}

// makeDirsReadOnly makes a best-effort attempt to remove write permissions for dir
// and its transitive contents.
func makeDirsReadOnly(dir string) {
	type pathMode struct {
		path string

	default:
		return false

	case objabi.R_DWARFSECREF:
		out.Write32(uint32(sectoff))
		out.Write32(uint32(symdynid))
		out.Write16(ld.IMAGE_REL_ARM64_SECREL)

	case objabi.R_ADDR:
		out.Write32(uint32(sectoff))
		out.Write32(uint32(symdynid))
		if r.Size == 8 {
			out.Write16(ld.IMAGE_REL_ARM64_ADDR64)
		} else {
			out.Write16(ld.IMAGE_REL_ARM64_ADDR32)
		}

	case objabi.R_PEIMAGEOFF: